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Contents: how mRNA vaccines work | Delta variant
Moderna, Pfizer covid vaccines: What you need to know - The Washington Post
Launched in 1996, the International AIDS Vaccine Initiative (IAVI) is a nonprofit scientific research organization dedicated to addressing urgent, unmet global health challenges including HIV and tuberculosis.
In 2020 24 years later there is still no vaccine.
Dr. Anthony S. Fauci, the top infectious disease expert on the Trump administration’s coronavirus task force, estimate a vaccine could arrive in at least 12 to 18 months. This is optimistic. The record for developing an entirely new vaccine is at least four years.
Although scientists did create candidate vaccines for the coronaviruses SARS-CoV and MERS-CoV, these did not exit clinical trials or enter public use, partly because of lack of resources.
The COVID-19 effort is being fast-tracked.
Normally researchers need years to secure funding, get approvals and study results piece by piece.
There are already at least 254 therapies and 95 vaccines related to Covid-19 being explored.
|Phase 1||Tests on 20-100 healthy volunteers||2 yrs||37%|
|Phase 2||Cross sectional tests of several hundred volunteers |
with different ages and health conditions, for
side effects, Immune response
|Phase 3||Hundreds or thousands of volunteers |
tested for efficacy and safety.
Understanding How COVID-19 Vaccines Work | CDC
(196) COVID-19 vaccine basics: How the vaccines work - YouTube | MD Anderson
(196) How do mRNA COVID-19 vaccines work? - YouTube | PBS News Hour
How Pfizer's COVID-19 vaccine works: mRNA | FastCompany
It is 40%-60% more infectious or transmissable- i.e. spreads easier.
It may be more serious - Causes more severe illness, but more data is needed.
It's more important to get 2 doses of the vaccine.
The first dose which was 80-85% effective for Pfizer and Moderna with the original viruus is only 30-35% effective with the delta variant.
The vaccine is 88% effective after the second dose of the Pfizer vaccine.
Effectiveness after one dose of vaccine ( BNT162b2 (Pfizer– BioNTech) and ChAdOx1 nCoV-19 (Oxford–AstraZeneca) was notably lower among persons with the delta variant (30.7%; 95% confidence interval [CI], 25.2 to 35.7) than among those with the alpha variant (48.7%; 95% CI, 45.5 to 51.7); the results were similar for both vaccines. With the BNT162b2 vaccine, the effectiveness of two doses was 93.7% (95% CI, 91.6 to 95.3) among persons with the alpha variant and 88.0% (95% CI, 85.3 to 90.1) among those with the delta variant. With the ChAdOx1 nCoV-19 vaccine, the effectiveness of two doses was 74.5% (95% CI, 68.4 to 79.4) among persons with the alpha variant and 67.0% (95% CI, 61.3 to 71.8) among those with the delta variant.
Only modest differences in vaccine effectiveness were noted with the delta variant as compared with the alpha variant after the receipt of two vaccine doses. Absolute differences in vaccine effectiveness were more marked after the receipt of the first dose. This finding would support efforts to maximize vaccine uptake with two doses among vulnerable populations. (Funded by Public Health England.)